The present invention relates to metering devices, specifically to container metering devices, more specifically to container metering devices which force separation between the containers, and particularly to container metering devices especially adapted for use in packaging machines.
In a typical packaging operation, containers come to a packaging machine in a single random lane. The containers are then grouped and divided into lanes corresponding to the eventual pack pattern in the packaging for the containers. Each of the lanes must then be controlled as to the number of containers released to give the total number required for the pack pattern. This control is accomplished by providing a separation between the containers in the lane to allow mechanical counting, to allow introduction of an overhead flight, or for the like. An example of one type of metering device which has enjoyed commercial success is shown and described in U.S. Pat. No. 4,832,178.
In the operation of the device of U.S. Pat. No. 4,832,178, the containers are held by pins while the table-top conveyor slides underneath until the particular pins for the row of containers retracts below the tabletop conveyor allowing the row of containers to be released and travel with the table-top conveyor creating a gap between that row of containers and the next row of containers. It can then be appreciated that product separation is completely dependent on the friction between the containers and the table-top conveyor that moves the product. However, this friction can be inconsistent because the condition of the table-top conveyor varies due to water and/or product from the containers being spilled on the table-top conveyor. Thus, even though the pins have been withdrawn below the table-top conveyor, the containers can have a tendency to continue to slide on the table-top conveyor rather than travel with the table-top conveyor. If this occurs, the gap or separation between containers can be nonexistent or inconsistent. Consistent separation is required to allow efficient mechanical counting, the introduction of overhead flights, and the like. This has been a particular problem for high-speed operation and for greasy-type products such as tomato paste.
A need has arisen for a method providing separation of a range of varying sized products which can be easily and simply achieved when it is desired to meter different sized containers without the use of change parts and which mechanically separates the rows of containers.